Many thanks to Tom Seaberg of Minnesota (USA) for his extensive help in compiling the information below.

N.B. After the J.I. Case Plow Works Co. was taken over by Massey-Harris in 1928, some 20-30 and 12-20 tractors retained the Wallis name on the radiator and the serial no. plate. These tractors are listed under the Massey-Harris section of the register.